<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
div{width:0; height:0;
border-top:10px solid red; 
border-left:10px solid green; 
border-right:10px solid blue; 
border-bottom:10px solid red; 
margin:100px;}

</style>
</head>

<body>
<div></div>
</body>
</html>
